Management and Supervision
6.4 Quantity Control
6.4.1 Objectives
Most of DPWH contract is a “unit price and quantity contract”. The quantity control is one of the most important elements for project management as it directly relates with the project cost. The documents to be referred to for quantity control are GCC, SCC, Specifications, BOQ and Drawings.
The Engineer, in cooperation with the Project Inspector, should work to:
* Ensure that the methods used in the measurement of quantities meet the contract requirements and Specifications;
* Verify that the correct quantities of completed work are reported for progress payments.
Note that large quantities are not forgotten in the billings;
* Ensure that a new overall estimate is made for each progress estimate. If computed monthly work quantities are merely added on the previous period, it may result in cumulative errors;
* Check the quantity calculation back-up data submitted by the Contractor for monthly billings. Compare with the quantity estimate data of the detailed design stage;
* Ensure double payment will be avoided by checking field measurement notes (logbook) and drawings;
* Monitor the planned quantity and work progress. If there is any big difference, instruct the Contractor to identify the causes;
* Where appropriate, do additional checking to assure the sufficiency of the validation.
Do not wait until the final stage of construction as correction of over-quantity, especially for major items, would become impossible; and
* At the final statement stage, review all final quantities in details on all items.
No payment shall be made to any defective work until the Contractor meets the requirements, either by removal, replacement or reconstruction, and accepted by the Engineer.
6.4.2 Duties of Quantity Engineer
The Quantity Engineer (or the Project Inspector) is responsible for all quantity measurement and estimate. He should monitor all works executed by the Contractor and treat variations instructed by the Engineer.
His duties include:
* verify the quantities in the Contract BOQ through a check of quantity estimate data of the design stage;
* carry out quantity measurement at the field;
* keep up-to-date quantity records including field measurements;
* assist the Engineer in the review of shop drawings for quantity estimate;
* assist the Engineer in preparing weekly and monthly reports;
* evaluate variation orders and costs proposed by the Contractor;
* evaluate monthly statement and claims; and
* prepare forecast final quantity and construction cost and revise it from time to time.
6.4.3 Inspection Techniques
The following is a summary of recommended inspection techniques to be applied for quantity control:
* Verify that the items reviewed were measured in the units called for in the BOQ and that the methods of measurement prescribed in the contract were followed;
* Examine project records to ensure that all materials for payment were delivered and incorporated into the project or stockpiled for future incorporation;
* When payment is based on weight or mass, verify the accuracy of the measurements, including calibration of scales;
* Where payment is based on loads delivered to the project, either on a weight or volume basis, verify the procedures for assuring validity in receipt of haul tickets;
* For area or volume measurement, clarify whether measurement is based on actual dimensional checks to the extent necessary to verify the actual work performed (on-site measurement) or by dimensions in the approved drawings/plans; and
* Ensure that measurements were made at the proper time and prior to the subsequent placement (cover) of other courses of materials.
6.4.4 Bill of Quantities (BOQ)
The BOQ is an estimated quantity. It is subject to change in accordance with the measurement at the site or the shop drawings submitted by the Contractor reflecting the current site conditions. The quantity for earthworks in particular, has a risk of substantial change compared with the contract design drawings (plans) as a result of As-stake survey.
The BOQ provides information on the quantities of Works to be performed by the Contractor and a priced BOQ for use in the periodic valuation of Works executed for payment.
Works are itemized in the BOQ in detail to identify the different classes of Works, or between Works of the same nature carried out in different locations or in other circumstances/conditions which may lead to different considerations of cost.
* The BOQ contains items of work for the construction, installation, testing, and
* The BOQ is used to calculate the Contract Price. The Contractor is paid for the quantity of the work at the rate in the BOQ for each item.
* If the final quantity of any work differs from the quantity in the BOQ for the particular item and is not more than twenty five percent (25%) of the original quantity, provided the aggregate changes for all items do not exceed ten percent (10%) of the Contract price, The Engineer shall make the necessary adjustments to allow the changes subject to applicable laws, rules, and regulations.
* The Contractor must provide the Engineer with a detailed cost breakdown of any rate in the BOQ.
6.4.5 Measurement and Evaluation
The Works shall be measured and valued for payment. The Contractor shall show in application of his statement for Interim Payment and Completion the quantities and other particulars detailing the amounts which he considers to be entitled under the Contract.
Whenever the Engineer requires any part of the Works to be measured, reasonable notice shall be given to the Contractor who shall:
(a) Promptly either attend or send another qualified representative to assist the Engineer in making the measurement; and
(b) Supply any particulars requested by the Engineer.
If the Contractor fails to attend or send a representative, the measurement made by the Engineer shall be accepted as correct.
Except as otherwise stated in the Contract and notwithstanding local practice,
(a) Measurement shall be made of the net actual quantity of each item of the Permanent Works in accordance with the Specifications; and
(b) The method of measurement shall be in accordance with the BOQ or other applicable schedules.
Quantity Control should also take into account any variations approved by the Engineer during the project implementation for quantity monitoring, including:
* increase or decrease the quantity of any work included in the Contract,
* omit any such work;
* change the character or quality or kind of any such work;
* change the levels, lines, position and dimensions of any part of the Works;
* execute additional work of any kind necessary for the completion of the Works; and
* change any specified sequence or timing of construction of any part of the Works.
The Engineer shall evaluate each item of work, applying the measurement agreed or determined in the above and the appropriate rate or price for the item in the Contract.. Any item of work included in the BOQ for which no rate or price was specified shall be considered as included in other rates and prices in the BOQ and will not be paid for separately, in principle.
6.4.6 Monitoring and Estimate of Final Quantity
The Engineer shall monitor work quantities provided in the BOQ, especially in the As-staked plan, shop-drawings and monthly billings. The Engineer shall monitor the progress of work item, especially major items and earth works, against the BOQ and forecast the final quantity. If any items are seemed to exceed the planned quantity in the BOQ, he must evaluate and take appropriate actions to correct and/or propose measures to control the project cost within the budget.
6.5 Documentation
The project implementation requires many types of reports and records. The objectives of recording and reporting are to keep the project information and data as evidence of proper project implementation, correct processing of payment, report the project status to CO, RO, DEO and funding agencies (local/foreign).
The Engineer shall keep and maintain the following project data during the implementation (construction and maintenance period) and handover them to the concerned RO and DEO after the final taking over of project for maintenance by DPWH.
Table 6.17 Checklist of Project Documents Classification of Data at the
Engineer’s Office during Implementation
Data Type Hand-over to
Hard Copy Data
Electronic Data
Administration Office (DPWH)
Maintenance Office (DPWH)
Contract Documents Yes Yes
Correspondence (Letters) Yes Yes
Progress Report (monthly, quarterly) Yes Yes Yes
Billing and Payment Yes Yes Yes
Completion Report Yes Yes Yes
Shop Drawings Yes
As-built Drawings Yes Yes Yes
Minutes of Meetings Yes Yes
Inspection Sheet / Instruction Sheets Yes
Quality Control Data Yes Yes
Quantity Measurements Yes Yes Yes
EMP Data Yes
Other Miscellaneous Data Yes
The Administration and Maintenance Office of DPWH shall take over important documents which are required for administration and maintenance. These offices shall keep them for a certain period in accordance with regulations and requirements.
6.5.1 Progress Reports
The Engineer shall accomplish a monthly progress report for submission to the Implementing Office, funding institutions and other concerned agencies.
The report shall contain the following:
Table 6.18 Progress Report
Executive Summary Need Need
Main Report
- Project Information and Impact Need Need
- Construction Progress and Status Need Need
- Construction Status (Progress) Need Need
- Project Activities and Accomplishment of Quantity Need Need
- Material Testing and QC Activities Need Need
- Contractor’s Resources Need Need
- Issue and Problems, and Recommendations and Actions
Need Need
Attachments
- Bar Chart and S-Curve Need Need
- Status of Construction Equipment Need Need
- Status of Contractor’s Personnel Need Need
- Weather Report Need Need
- Progress Photographs Need Need
- Letters (List)* Need Need
Consultancy Services for Construction Supervision
- Overall Implementation Need -
- Manning Schedule Need -
- Organization Set-up
Need
The Office of the Engineer Note: Attach letters if they are very important, such as claim or action plans for recovery of delay.
6.5.2 Project Logbook
The Engineer shall accomplish the Project Logbook to keep a complete record of daily entries. The logbook shall be duly signed by the Engineer and concurred by the Contractor in accordance with DO No. 216, Series of 2000.
The logbook provides the following:
* Permanent file evidence that inspections are being made as required by the Contract
and Specifications;
* Basis for acceptance of completed work;
* Record of field conditions and contractor’s performance;
* Record of daily project activities, equipment, manpower and resources at site; and
* Record of daily management and supervision activity, observations, findings, resolution of identified problems, claims, and any other topics of interest.
The logbook should be clear and concise with facts. The record should be accurate and specific since the content may be used in evaluating contract claims. If no work was performed at all, a daily report shall be stated “No Work” and reasons. The daily record of personnel and equipment is particularly important in view of the possibility of Contractor’s claims for stand-by cost of the idled personnel and equipment. Verify that discussions with the Contractor are confirmed in writing and are made a part of the official project file.
The record contains the following:
1) Date and weather conditions;
2) Work of staking party;
3) Work of inspectors;
4) Work of office staff;
5) Construction work in progress;
6) Contractor’s crew, equipment and materials on each item;
7) Inspections, decisions, and details discussed with inspectors;
8) Instruction to Contractors;
9) The substance of important communications and discussions with the Contractors, concerning activity, progress, change, interpretation of specifications, etc.; and
10) Any information not covered in other records, which might have bearing in case of future disagreement, such as difficulties encountered in construction and their causes, delays caused by breakdown of equipment, etc.
If the operation is on a shift basis, the entries should be signed and properly endorsed.
The Materials Engineer is also required to keep a Log Book on Material Quality Control (per Memorandum dated 28 October 2004 on Revised Format Submitting Monthly Materials Control Report) recording quality control activities and other information and observation relevant to materials quality control in addition to the above.
After completion of the project, the logbook shall be turned over to the Implementing Office.
CONTRACT I.D. NO. : ___________________________________
PROJECT NAME : ___________________________________
LOCATION : ___________________________________
CONTRACTOR : ___________________________________
DATE : ___________________________________
WEATHER (AM) : ___________________________________
(PM) : ___________________________________
Scheduled : ________________________
Actual: ________________________
Slippage: ________________________
6.5.3 Correspondence
Letters are official communication between the Engineer and the Contractor2.
It is very common that the Engineer gives verbal instructions so these should be officially confirmed in writing.
The letters are filed in order and kept at the office as follows:
Table 6.19 Responsible Office for Securing the Documents Foreign-Funded Project with
Consultant
Locally-Funded Project without Consultant
Out-Going - Employer (DPWH) - DPWH (CO, RO, DEO, etc)
- Contractor - Contractor
- Others - Others
In-Coming - Employer (DPWH) - DPWH (CO, RO, DEO, etc)
- Contractor - Contractor
- Others - Others
6.5.4 Progress Photographs Photographs shall be taken for:
* Periodic record of work progress (weekly or monthly);
* Construction record of important work activities, including concreting, laying of Asphalt Concrete pavement, etc.;
* Construction record of the Works which will be covered after construction such as reinforcement, foundation, back fill, drainage pipes, base, subbase, etc.;
* Construction record of the Works which are removed after construction, such as excavation, demolition of obstacles, tree cutting, etc.;
* Material and quality control tests such as field density, CBR, compression, etc.;
* Defects, wrong workmanship, damage by flood, wrong traffic safety control;
* Mobilization of equipment and materials; and
* Any other specific issues and incidents, including visit of very important persons.
The use of digital camera is recommendable since digital files are easily transferred and stored.
Figure 6.13 illustrates progress photographs.
2 Communication thru E-mail is one of the efficient communication means and the record (print-out) should be kept in letter files for reference.
Figure 6.19 Progress Photographs
Damage of Outlet & Apron of Box Culvert by Scouring Steel Sheet Piling for Foundation
Completion of Repair (Scouring Protection Works) Steel Sheet Piling for Foundation
Damage of Roadway by Landslide Landslide Countermeasure Design
Completion of Countermeasure Works Completion of Earthworks Start of Removal of Head of Slide-Mass
Flood by Heavy Rain Rejection of Stone Masonry Work because of Insufficient Mortar Fill
Jun. 2002 Apr. 2005
Dec. 2005 Jul. 2005
Progress Record for Scouring Protection Works
Removal of Head of Slide-Mass Gabion
Retaining Wall
Sub-soil / Road Side Drainage
A-A SECTION Jun. 2002
Mar 2003
Jun. 2005 Dec. 2004
Mar. 2006
Typical Section
Progress Record for Landslide Countermeasure Works
Mar. 2006